Leak-proof cartridges housing cements, caulking compounds or the like



H. A. r LEAK-PROOF CARTRIDGES HOUSING CEMENTS, GAULKING COMPOUNDS OR THE LIKE Filed March 21, 1966 FEGB ATTORNEY.

United States Patent 3,319,841 LEAKJFROOIF CARTRIDGES HQUSING CEMENTS, CAULKING COMPOUNDS OR THE LIKE Howard A. Berg, Malverne, N.Y., assignor to Columbia Cement Company, Inc, Brooklyn, N.Y., a corporation of New York Filed Mar. 21, 1966, Ser. No. 535,792 Claims. (Cl. 222-3865) The present invention relates to cartridges loaded with cements, caulking compounds, greases or other viscous preparations, and more particularly to the type comprising a tube having a discharge nozzle at one end, and a piston or plunger closing its other end and movable therein to eject the tubes contents, by use of a caulking gun into which the cartridge is fitted.

A major fault heretofore experienced with cartridges of this general class, was that pressures built up within the laden tube due to gases liberated by volatile contents therein, causing the plunger to become loose and even leave the tube, allowed the fill to creep and spill out, while the cartridge was in transit or while on the shelf. So before bein put to use, there was much loss and inconvenience. Various attempts have been made t remedy this unfavorable condition with special plunger and tube constructions, but these were costly to make, requiring expensive dies and tubes of cardboard were unsuitable in most such instances.

It is therefore the principal object of this invention to provide a novel and improved cartridge structure in which the tube is of cardboard as is the common practice in order to keep the cost low, but the plunger is so fashioned that it stays put at any position it is placed or pushed to within the tube. Hence there is no leakage or spilling at any time during transit, while on the shelf, and when the cartridge is removed from the gun, only part empty.

A further object of this invention is to provide a novel and improved cartridge structure whose plunger remains in leak-tight association with the cardboard tube and can be moved only towards the nozzle end thereof.

Still another object of this invention is to provide a novel and improved cartridge construction of the character set forth, having the mentioned attributes, and which at most adds a negligible amount to the heretofore prevailing cost of production because of the change to be made in the plunger per se, which makes it effective for carrying out the functions for which it is designed.

Other objects and advantages will become apparent as this disclosure proceeds.

For one practice of this invention, the cartridge comprises a cardboard tube having a discharge nozzle at one end and a plunger closing its other end, which plunger is inserted after the tube is filled with cement, caulking compound or other viscous product which is to be ejected by use of a caulking gun in which the cartridge is set. The plunger is a stamped sheet metal cup of material having some resiliency. It is positioned with its mouth end away from the nozzle end of the tube, and its peripheral wall is in leak-tight frictional engagement with the interior surface of said tube. A plurality of equispaced, slightly outwardly extending prongs of triangular shape are struck from the material of the cups peripheral wall so the apex of each prong is at the mouth rim line of the cup before the prong is shifted to be a bit outwardly; said rim line having been cut for the making of said apex. This brings into being two additional sharp teeth on said peripheral wall, at each prong struck, so there is a group of three teeth in angularly spaced relation which bear into the cardboard wall, holding the plunger against movement away from the nozzle end of the tube, but permitting a plunger to be moved towards the nozzle end. If the number of prongs struck is for example three as illustrated herein, then an additional six prongs have automatically been created, for holding the plunger against outward movement, but permitting movement thereof towards the discharge end of the cartridge.

In the accompanying drawing forming part of this specification, similar characters of reference indicate corresponding parts in all the views.

FIG. 1 is a perspective view of a cartridge embodying the teachings of this invention.

FIG. 2 is a perspective view of a caulking gun, and indicated sparsely by dot-dash lines, said cartridge is shown set therein.

FIG. 3 is an enlarged, fragmentary longitudinal view, partly in section, showing the ram of the gun acting on the plunger or the cartridge, so upon movement of the ram, the contents of the tube will be ejected.

FIG. 4 is a fragmentary perspective view of a prong formation at the mouth-end of the cup member which is the plunger in said cartridge.

In the drawing, the numeral 15 designates generally a cartridge comprising a cardboard tube 16, having a discharge nozzle 17 at one end, and a plunger indicated generally as 18, closing, and wholly inward a bit at its other end; said tube being filled with a viscous compound 19. Said nozzle may be of plastic with its tip closed, which is to be pierced or a slight piece cut off when it is desired to eject the compound. As a suggestion, not shown but believed readily understood by those versed in the art without the necessity for further illustration, the nozzle may have a discharge orifice closed by a removable cap. The plunger is a stamped cup made of sheet metal having some resilient quality. It is positioned with its mouth end away from the nozzle end of the tube, and its peripheral wall 20 is in leak-tight frictional engagement with the interior surface of said tube 16. Said peripheral wall is tapered a bit as at 21, where it joins the floor wall 22 of the cup to facilitate entering same into the tube, and its mouth rim edge 23, may be minutely flared as shown at 24, so the inner surface of the tube is slightly scraped by plunger movement.

Of importance to note are the equi-spaced, slightly outwardly extending prongs 25, each of which is preferably of triangular shape, with its apex 25' at the mouth rim edge of the plunger; such prongs in being struck from the material of the peripheral wall of the plunger, having caused a rupture 26 in said rim edge, thereby creating the slightly spaced teeth 27, 28, one at each side edge of the struck prong 25.

Even when the peripheral wall 20 of the plunger is true cylindrical, the tips of the teeth 27, 28 will be bent slightly outwardly, because in rupturing the mouth rim of the cup form constituting the plunger 18, said rim will spring a little and become slightly enlarged. However by providing the slight fiare 24, the tips of the teeth 27, 28 will surely engage the tube 18, or in any event, by a separate operation, the teeth 27, 28 may be purposely bent out a bit. When the material of the plunger has some resilient quality, the teeth 27, 2 8, are effective without further deformation.

The cartridge comes to market with its plunger 18 so positioned within the laden tube 16, that the mouth rim edge of the plunger cup is spaced a bit from the tube end, so all the teeth 25, 27 and 28 are dug in the tube wall. It is evident that the plunger 18 can be pushed towards the nozzle 17, but all the teeth prevent reverse movement thereof.

To eject the cartridge contents 19, the cartridge 16 is set into a caulking gun 29 in well known manner, so its front end bears against the notched front cap 30, with its nozzle 17 extending through the notch 31, and the trigger 32 is worked to bring the ram plate 33' into the plunger cup 18 and bear against the floor wall 22 of said cup. Upon opening the discharge orifice of the nozzle, or providing it with one, the material 19 will be ejected as the ram 33 is caused to move forwardly towards the nozzle.

It is evident that the groups of teeth, each group comprising 25, 27, 28, prevent rearward movement of the plunger 18, which function is especially called for when the cartridge is out of the gun, meaning, before the cartridge is put to use, or after it is removed from the gun, only partly empty. Of course, while out of the gun, the nozzle is closed by a cap, plug or otherwise, and it is found that many fills will clot the open discharge orifice of a nozzle, if let stand awhile. This, of course, is resorted to only after there has been some intentional depletion of the contents, and the cartridge is to be put away for use at some other time.

This invention is capable of numerous forms and various applications without departing from the essential features herein disclosed. It is therefore intended and desired that the embodiment set forth herein shall be deemed merely illustrative and not restrictive and that the patent shall cover all patentable novelty herein set forth; reference being had to the following claims rather than to the specific description and showing herein, to indicate the scope of this invention.

I claim:

1. In a cartridge of the character described, a cardboard tube housing a viscous mass to be ejected therefrom; said tube terminating in a discharge nozzle at one end, and a cup positioned within said tube, with its mouth facing and spaced from the other end of said tube; said cup serving as a plunger in said tube, adapted for movement therein for ejecting said mass through said nozzle; the peripheral wall of said cup having a plurality of prongs struck therefrom so the mouth rim of said cup is ruptured at each prong, thereby forming two teeth at each prong in said mouth rim, one tooth aside each side edge of the prong; said prongs extending away from said nozzle; said prongs and teeth being bent outwardly and engaging said tube.

2. A cartridge as defined in claim 1, wherein each prong is triangular; the tip of each prong being a point; said tips being away from said nozzle.

3. A cartridge as defined in claim 2, wherein the mouth of the cup is minutely flared; the prongs being struck in said flare.

4. A cartridge as defined in claim 1, wherein said cup is of a material having some resilient quality.

5. A cartridge as defined in claim 1, wherein the cup is a sheet metal stamping.

References Cited by the Examiner UNITED STATES PATENTS 2,661,126 12/1953 Spencer 222-386 2,933,221 4/1960 Rand et al. 222-391 3,211,347 10/1965 Phillips 222327 ROBERT B. REEVES, Primary Examiner.

KENNETH N. LEIMER, Assistant Examiner. 

1. IN A CARTRIDGE OF THE CHARACTER DESCRIBED, A CARDBOARD TUBE HOUSING A VISCOUS MASS TO BE EJECTED THEREFROM; SAID TUBE TERMINATING IN A DISCHARGE NOZZLE AT ONE END, AND A CUP POSITIONED WITHIN SAID TUBE, WITH ITS MOUTH FACING AND SPACED FROM THE OTHER END OF SAID TUBE; SAID CUP SERVING AS A PLUNGER IN SAID TUBE, ADAPTED FOR MOVEMENT THEREIN FOR EJECTING SAID MASS THROUGH SAID NOZZLE; THE PERIPHERAL WALL OF SAID CUP HAVING A PLURALITY OF PRONGS STRUCK THEREFROM SO THE MOUTH RIM OF SAID CUP IS RUPTURED AT EACH PRONG, THEREBY FORMING TWO TEETH AT EACH PRONG IN SAID MOUTH RIM, ONE TOOTH ASIDE EACH SIDE EDGE OF THE PRONG; SAID PRONGS EXTENDING AWAY FROM SAID NOZZLE; SAID PRONGS AND TEETH BEING BENT OUTWARDLY AND ENGAGING SAID TUBE. 